Typically, a cased hydrocarbon well includes a borehole drilled in a geological formation, a fluid-filled casing disposed in the borehole and cement disposed in an annulus between the casing and the formation. During well logging operations, it can be important to obtain information as to the condition of the casing and the material behind the casing (e.g., cement, water, drilling mud, air, etc.). Ultrasonic logging tools can be used to determine characteristics of the casing and the material behind the casing such as, for example, the thickness of the casing and the acoustic impedance of the material behind the casing. Typically, these measurements are obtained by exciting a casing thickness mode resonance using an ultrasonic acoustic pulse, measuring the temporal period and amplitude decay rate of the acoustic response, and interpreting the data. The thickness mode resonance of the casing in response to the acoustic pulse generally depends on the cement-casing bond, expressed as an acoustic impedance of the cement, and the casing thickness.